PASADENA, California (CNN) --NASA's remote controlled rover Spirit is safely sitting on the surface of planet Mars sending images to Earth, where excited scientists will examine data for signs of water and life.

CNN's Miles O'Brien is covering Spirit's amazing journey from mission control at NASA's Jet Propulsion Laboratory and filed this report:

O'BRIEN: The Spirit has landed. Quite a marked contrast to what happened four years ago, when NASA tried to land a lander on Mars. The Mars Polar Lander crashed when it prematurely shut off its rocket engines, mistaking the jolt of the landing gear deploying for touchdown.

This time it went off without a hitch -- and then some. As a matter of fact, if anybody had expected this result last night, they sure weren't saying anything about it.

A joyous pandemonium erupted in the mission control room when the first signals from the rover were received this morning -- after 4 solid years of work and a 303-million-mile journey and seven months of travel time. The landing happened, the tones were sent back, and before too long, amazingly, a series of pictures came back.

The images showed the Martian surface in the afternoon and Spirit sitting in the midst of what may be a dry lake bed. Scientists would like to prove that by analyzing data from the rover during the next few months.

The airbags which protected Spirit on impact have deflated. Its petals have opened up, which protected it as well. Solar arrays opened and a mast with a stereoscopic camera has been raised.

It will take nine days before this team of scientists is expected to move Spirit off its platform and begin moving around the planet's surface.

It will go across the exploration field looking for interesting rocks. It has a tool which will be able to auger into rocks and analyze them to get a sense of what they can tell us about the history of the planet, and what may have happened to the Martian water and whether Mars ever hosted any forms of life.

It's hard to believe -- when you look at it that this cold, arid, unforgiving place that scientists believe was once warm and wet -- there's a good chance there probably was life there at one time. Where did it all go?

The science team is already working, looking at these new images. Obviously at this early point they're not going to come up with any smoking-gun evidence. They're going to continue looking at these initial images and go through a really methodical checkout period.

In nine days they will start moving the rover. They'll pick a rock, probably one very close by. They'll go up to it. They'll use this tool to pick off the rock's outer surface. Then they'll take a close look at it. It might very well be that on the first rock they'll see very clear signs of sediment. And sediment is caused by water being on top of a place for a long time and that would be pretty much smoking-gun proof that there was water there.

Who knows, they may even get really lucky -- because it has a microscope on it -- they might even find a fossil, and wouldn't that be something?